Process for solubilizing organic or mineral salts in organic solvents

ABSTRACT

The invention provides a process for solubilizing an organic or mineral salt in an organic solvent, said process comprising contacting an organic or mineral salt of the formula A -  M + , wherein A -  represents a mineral or organic anion and M +   represents a cation selected from the group consisting of the cation NH 4   +   and its derivatives and the cations derived from the metals of the groups I A , II A , III A , IV A , V A , VI A , VII A , VIII, I B , II B , III B , IV B  and V B  of the periodic table, with at least one sequestering agent which is soluble in said organic solvent, said sequestering agent having the formula: 
     
         N[CHR.sub.1 --CHR.sub.2 --O--(CHR.sub.3 --CHR.sub.4 --O).sub.n --R.sub.5 
    
      ] 3                                                    (I) 
     wherein n is an integer from 0 to 10 inclusive; R 1 , R 2 , R 3  and R 4 , which can be the same or different, are each a hydrogen atom or an alkyl radical having 1 to 4 carbon atoms; R 5  is an alkyl radical having 1 to 12 carbon atoms, a cycloalkyl radical having 3 to 12 carbon atoms, a phenyl radical, a radical of the formula ##STR1## or a radical of the formula ##STR2## and m is an integer from 1 to 12 inclusive. The process makes it possible to utilize the A -  M +   salt as a reactant in solvents in which such reaction has not heretofore been possible, or to extract the A 31  M +   salt from a solution containing it.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention provides a process for solubilizing an organic ormineral salt. More particularly, the invention provides a process forsolubilizing an organic or mineral salt in an organic solvent in whichthe organic or mineral salt is not soluble, or for increasing thesolubility of an organic or mineral salt in an organic solvent.

2. Background of the Prior Art

The problem of solubilizing salts is a significant one. It is well knownthat many organic and mineral salts are either insoluble or lacksatisfactory solubility in the majority of organic solvents usedindustrially.

Organic solvents may be classified according to their ability todissolve a salt. This classification takes into account various factors,such as, specifically, the polar and protonic character of thesesolvents. It is well known to those skilled in the art that polarsolvents, i.e. solvents having a high dielectric constant, dissolvesalts more readily than solvents of an apolar character, i.e. thosehaving a low dielectric constant. It is also well known that the bestpolar solvents are the protonic polar solvents, i.e. solvents having ahigh dielectric constant and possessing hydrogen atoms of an acidcharacter.

Thus, the best organic solvents to dissolve salts include formamide,acetamide, formic acid, hexamethylphosphorotriamide (H.M.P.T.),dimethylsulfoxide, sulfolane, N-methylpyrrolidone, dimethylformamide,dimethylacetamide, methanol and acetone, while the less good onesinclude chloroform, methylene chloride, carbon tetrachloride,trichloroethylene, dichloroethane, chlorobenzene, orthodichlorobenzene,benzene, toluene, the xylenes, cyclohexane and hexane.

It should be noted that the difficulty of industrial application ofthese solvents increases generally when proceeding from the solvents oflesser capability to the better ones. In fact, the better solvents mayreact with the salts to be dissolved and yield secondary products. Someof them are highly toxic, such as HMPT, while others, such asdimethylsulfoxide, are malodorous and lack thermal stability.Furthermore, all of these products are expensive. It is obvious thatpersons skilled in the art prefer, when possible, to use an apolarsolvent such as toluene and the xylenes, for example, which are lessonerous and more easily handled, because of their low toxicity and theirthermal and chemical stability.

However, it is very frequently the case that a given salt may bepractically totally insoluble in any of the apolar solvents and onlypartially soluble in the protonic polar solvents, with the maximumsolubility being attained in the best of the protonic polar solvents.

It is readily seen therefore, how important it would be to be able tosolubilize a salt in a solvent in which it is initially insoluble, butwhich solvent is easier to apply industrially, or to increase thesolubility of the salt in such a solvent. This dual objective is in factattained by the present invention, with important industrialapplications being set forth hereinafter.

From the prior art, a certain amount of work leading to partialsolutions in this field is known. Thus, French Patent Application No.69.43879, published under No. 2,026,481, describes macrocyclic polyethercompounds. These compounds can form complexes with the cations ofcertain metallic compounds, in particular with the salts of alkalimetals and alkaline earth metals. These complexes are analyticalreagents for use in nonhydroxylated media in which uncomplexed metalcompounds are normally insoluble. The macrocyclic compounds described insaid French patent application have 15 to 30 atoms in the polyether ringand are composed of 5 to 10 --O-X units, wherein X, for a particularcompound, is either (a) --CHR₁ -CHR₂ - or (b) --CHR₁ - CR₃ R₄ -CHR₂ -wherein R₁, R₂, R₃ and R₄ are each a hydrogen atom or an alkyl radical.

It is evident that these compounds, which are most commonly called"crown ethers", have a highly sophisticated structure. It follows thatthe process for their preparation is a delicate operation. Withoutdoubt, one of the major disadvantages of the use of these crown ethersis their extremely high cost, which is a reflection of their complexityand manner of preparation. Another important disadvantage is that, on apractical level, according to the patent application cited above, thesecompounds can only be used with alkali metal compounds and withcompounds of the alkaline earth metals having atomic weights greaterthan 40.

Another French patent application, Patent Application No. 70.21079,published under No. 2,052,947, also describes macrobicyclic compoundscapable of complexing salts and thus rendering them soluble in solventsin which they are normally insoluble. These macrobicyclic compounds,commonly called "cryptants", also have an extremely sophisticatedstructure, which again implies the disadvantages emphasized above withrespect to the crown ethers.

Thus, a real need exists on an industrial level to have available asimple-to-apply process for solubilizing a mineral or organic salt in anorganic solvent in which it is not initially soluble or for augmentingthe solubility of a mineral or organic salt in an organic solvent. Thework of the present applicant lead to the development of such a process.

BRIEF SUMMARY OF THE INVENTION

The present invention thus has as its object a process for solubilizingan organic or mineral salt in an organic solvent in which the salt isnot initially soluble, or for augmenting the solubility of an organic ormineral salt in an organic solvent, said process comprising contactingan organic or mineral salt of the formula A⁻ M⁺, wherein A⁻ is anorganic or mineral anion and M⁺ is a cation selected from the groupconsisting of the NH₄ ⁺ cation and its derivatives and the cationsderived from the metals of groups I_(A), II_(A), III_(A), IV_(A), V_(A),VI_(A), VII_(A), VIII, I_(B), II_(B), III_(B), IV_(B) and V_(B) of theperodic table, with at least one sequestering agent soluble in theorganic solvent, said sequestering agent having the formula

    N[CHR.sub.1 -CHR.sub.2 -O-(CHR.sub.3 -CHR.sub.4 -O).sub.n -R.sub.5 ].sub.3

wherein n is an integer from 0 to 10 inclusive; R₁, R₂, R₃ and R₄, whichcan be the same or different, are each a hydrogen atom or an alkylradical having 1 to 4 carbon atoms; R₅ is an alkyl radical having 1 to12 carbon atoms, a cycloalkyl radical having 3 to 12 carbon atoms, aphenyl radical, a radical of the formula ##STR3## or a radical of theformula ##STR4## and m is an integer from 1 to 12 inclusive, to afford acomplex of said salt and said sequestering agent, said complex havingthe formula

    [N[CHR.sub.1 -CHR.sub.2 -O-(CHR.sub.3 -CHR.sub.4 -O).sub.n -R.sub.5 ].sub.3 ].sub.y (M.sup.+ A.sup.-)                                 (II)

wherein y is greater than or equal to 1 and less than or equal to 3,said complex being soluble in said organic solvent.

DETAILED DESCRIPTION OF THE INVENTION

According to a first variation of the present invention, comprising asingle stage, the anhydrous organic or mineral salt and the sequesteringagent of formula (I) are contacted in a solution of said organicsolvent.

According to a second variation, comprising a single stage, the organicor mineral salt in an aqueous solution is contacted with thesequestering agent of formula (I) in solution in said organic solvent,said organic solvent in this variation being immiscible with water.

According to a third variation of the present process, in a first stagethe anhydrous mineral or organic salt in solution in a third solvent iscontact with the sequestering agent of formula (I) in solution in thesame third solvent; in a second stage, the third solvent is eliminated;and in a third stage, the product resulting from the second stage iscontacted with said organic solvent.

According to a fourth variation, in a first stage the anhydrous mineralor organic salt and the sequestering agent of formula (I) are contactedwith each other in the absence of any solvent, and in a second stage theproduct resulting from the first stage is contacted with said organicsolvent.

These four variations correspond to different embodiments of the processaccording to the invention. Those skilled in the art will select fromamong these four variations according to the nature of the problem to besolved, particularly taking into account the nature of the salt to besolubilized.

The third variation affords ready isolation of the complex of formula(II) obtained at the end of the second stage.

The fourth variation also affords isolation of the complex of formula(II) at the end of the first stage, without it being necessary to employa third solvent.

The sequestering agents preferred for use in the process of theinvention are those wherein R₁, R₂, R₃ and R₄ are each a hydrogen atomor a methyl radical, with R₅ and n being defined as hereinabove.

Among the preferred sequestering agents, the ones which are particularlypreferred are those wherein n is greater than or equal to 0 and lessthan or equal to 6 and wherein R₅ is an alkyl radical having 1 to 4carbon atoms. Exemplary of the most preferred sequestering agents arethe following:

(a) tris(3-oxabutyl)amine of the formula:

    N--(CH.sub.2 --CH.sub.2 --O--CH.sub.3).sub.3

(b) tris(3,6-dioxaheptyl)amine of the formula:

    N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.3).sub.3

(c) tris(3,6,9-trioxadecyl)amine of the formula:

    N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.3).sub.3

(d) tris(3,6-dioxaoctyl)amine of the formula:

    N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.2 H.sub.5).sub.3

(e) tris(3,6,9-trioxaundecyl)amine of the formula:

    N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.2 H.sub.5).sub.3

(f) tris(3,6-dioxanonyl)amine of the formula:

    N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.3 H.sub.7).sub.3

(g) tris(3,6,9-trioxadodecyl)amine of the formula:

    N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.3 H.sub.7).sub.3

(h) tris(3,6-dioxadecyl)amine of the formula:

    N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.4 H.sub.9).sub.3

(i) tris(3,6,9-trioxatridecyl)amine of the formula:

    N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.4 H.sub.9).sub.3

(j) tris(3,6,9,12-tetraoxatridecyl)amine of the formula:

    N--(CH.sub.2 --CH.sub.2 --O--CH.sub.1 --CH.sub.2 --O--CH.sub.1 --CH.sub.2 --O--CH.sub.1 --CH.sub.2 --O--CH.sub.3).sub.3

Additional exemplary sequestering agents include:

(h) tris(3,6,9,12,15,18-hexaoxanonadecyl)amine of the formula:

    N[CH.sub.2 --CH.sub.2 --O--(CH.sub.2 --CH.sub.2 --O).sub.5 CH.sub.3 ].sub.3

(l) tris(4-methyl-3,6-dioxaheptyl)amine of the formula: ##STR5## (m)tris(2,4-dimethyl-3,6-dioxaheptyl)amine of the formula: ##STR6##

In the definition of the invention given hereinabove, it is obvious thatM⁺ represents both monovalent and polyvalent cations. The same is truefor the anion A⁻, i.e. it represents either monovalent or polyvalentanions.

In spite of the fact that the work of the prior art would lead theresearcher to orient his efforts toward complexing molecules of verycomplicated cyclic structures, the present applicant has discovered thatmuch simplier molecules of a noncyclic structure, and much easier toobtain, yield excellent results.

The amines used in the process of the invention are known as such in theprior art. Thus, French Pat. No. 1,302,365 (corresponding to U.S. Pat.No. 2,928,877) describes a process affording the tertiary amines N--(CH₂--CH₂ --O--CH₃)₃ and N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ as byproductsof the synthesis of the corresponding primary and secondary amines,those primary and secondary amines being products of interest asintermediates in the synthesis of pharmaceutical substances, ascorrosion inhibitors, as intermediates in the synthesis of agriculturalchemicals, and in emulsifiers. The field of application of the compoundsobtained in French Pat. No. 1,302,365 thus is quite remote from the useof the compounds of formula (I) in the process of the present invention.

The process of the present invention is particularly suitable forsolubilizing A⁻ M⁺ salts wherein A⁻ is an organic or mineral anion andM⁺ a cation selected from the group consisting of:

[i] NH₄ ⁺ and its RNH₃ ⁺ derivatives wherein R is an alkyl or arylradical; and

[ii] the cations derived from the metals Li, Na, K, Rb, Cs, Mg, Ca, Sr,Ba, Sc, Y, La and the lanthanides, Ac and the actinides Ti, Zr, Hf, V,Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cu,Ag, Au, Zn, Cd, Hg, Al, Ga, In, Tl, Ge, Sn, Pb, Sb, Bi.

However, this preference does not limit the invention in any sense; itderives solely from interest in the process according to the inventionon the industrial level.

This same interest also leads to a consideration of the process of theinvention as being more particularly, but not exclusively, suitable forsolubilizing A⁻ M⁺ salts wherein A⁻ is selected from the groupconsisting of:

[i] on the one hand, the mineral anions such as SCN⁻, O═C═N⁻, Cl⁻, Br⁻,H⁻, I⁻, F⁻, CN⁻, SH⁻, S⁼, OH⁻, HSO₃ ⁻, ClO₄ ⁻, BrO₄ ⁻, NH₂ ⁻, NO₃ ⁻, NO₂⁻, BF₄ ⁻, BrO⁻, ClO⁻, BH₄ ⁻, SO₃ ⁻⁻, PO₄ ⁻³, CO₃ ⁻⁻, SO₄ ⁻⁻, ClO₃ ⁻,BrO₃ ⁻ and AlH₄ ⁻ ; and

[ii] on the other hand, the organic anions derived, for example, from:

[a] aliphatic alcohols, such as, for example, methanol (CH₃ O⁻) and itshigher homologs, cyclopentanol (C₅ H₉ O⁻), cyclohexanol (C₆ H₁₁ O⁻), andbenzyl alcohol ##STR7## and its higher homologs; [b]0 phenols, such as,for example, phenol ##STR8## and its derivatives, such as picric acid##STR9## naphthols, such as α-naphthol ##STR10## and β-naphthol##STR11## substituted phenols, for example ##STR12## diphenols, forexample ##STR13## and bisphenols, for example ##STR14## [c] thiols, suchas, for example, methylmercaptan (CH₃ S⁻) and its higher homologs, andbenzylmercaptan ##STR15## and its homologs; [d] thiophenols, such as,for example, thiophenol ##STR16## and alkylthiophenols, for example,##STR17## [e] carboxylic acids, such as, for example, acetic acid (CH₃COO⁻), its higher homologs and its derivatives, such as, for example,cyanoacetic acid (CNCH₂ COO⁻) and chloroacetic acid (ClCH₂ COO⁻);versatic acids, i.e. saturated tertiary monocarboxylic C₉ -C₁₁ acids,for example, ##STR18## phenylacetic acids ##STR19## and its homologs);phenoxypropionic acids, for example, ##STR20## benzoic acids, forexample, ##STR21## and ##STR22## and naphthenic acids ##STR23## [f]sulfonic acids, such as, for example, methanesulfonic acid (CH₃ --SO₃ ⁻)and its higher homologs; benzenesulfonic acid ##STR24## and itshomologs; and naphthylsulfonic acid ##STR25## and its homologs; [g]amines, such as, for example, aliphatic amines, e.g. CH₃ NH⁻ and itshigher homologs; anilines, for example, ##STR26## and its homologs;##STR27## and benzylamines, e.g. ##STR28## and its homologs; [h] amides,such as, for example, aliphatic amides (CH₃ CONH⁻ and its higherhomologs), and aromatic amides ##STR29## and its homologs); [i] organiccompounds with a mobile hydrogen, such as, for example, the malonicesters [CH--(CO₂ CH₃)₂, for example]; chloroacetonitrile (Cl--CHCN) andits homologs; phenylacetonitriles, e.g. ##STR30## triphenylmethane##STR31## ##STR32## for example); phenylacetone ##STR33## andacetophenones, e.g. ##STR34## [j] silanols, such as, for example,##STR35##

It must be emphasized that the foregoing examples of anions are onlyillustrative and by no means limiting. In fact, any salt having a cationcorresponding to the definition given hereinabove may be treated by theprocess of the invention.

The selection of the sequestering agent most suitable for solubilizing agiven salt must principally take into account the M⁺ cation; the largerthe cation, the greater the number of oxygen atoms contained in themolecule of the sequestering agent should be. For example, potassiumpicrate in an aqueous solution intimately mixed with methylene chloridedoes not dissolve in this solvent. If a sequestering agent is addedaccording to the process of the invention, it is observed that the saltis solubilized. The extent of the dissolution will thus be greater withtris(3,6,9-trioxadecyl)amine, which contains three oxygen atoms in eachbranched chain attached to the nitrogen atom, than withtris(3,6-dioxaheptyl)amine, which contains only two oxygen atoms in eachbranched chain attached to the nitrogen atom. In contrast, for sodiumpicrate, because the Na⁺ cation is smaller than the K⁺ cation, bettersolubilization will be obtained with tris(3,6-dioxaheptyl)amine.

The solvent ought to satisfy a certain number of conditions: it mustinitially dissolve the sequestering agent; and it must also bechemically inert vis-a-vis the salt to be dissolved. (In the same way,it is necessary that the sequestering agent act only as a complexingagent vis-a-vis the mineral or organic salt.)

It must also be emphasized that the more pronounced the apolar nature ofthe solvent, the more the sequestering agent ought to have a lipophiliccharacter, i.e. the more carbon atoms should be present in thesequestering agent.

In order to obtain the best solubility, the greater the electron densityof the A⁻ anion, the more polar the solvent should be. Anions with ahigh electron density, i.e. the "hard" anions, are anions of small size,such as, for example, OH⁻, F⁻ and Cl⁻. "Soft" anions, which are of alarger size, are, for example, SCN⁻, ##STR36##

The sequestering agents used in the process according to the inventionare soluble in all of the usual organic solvents. More particularly, theprocess according to the invention solubilizes the salts described abovein the following solvents, taken individually or in mixtures: aliphaticsolvents such as hexane and cyclohexane; aromatic solvents such asbenzene, toluene, o-xylene, m-xylene and p-xylene; halogenated aromaticsolvents such as chlorobenzene, o-dichlorobenzene and1,2,4-trichlorobenzene; halogenated aliphatic solvents such aschloroform, methylene chloride, carbon tetrachloride,1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, and1,2,2-trichloro-1,1,2-trifluoroethane; and halogenated olefinic solventssuch as perchloroethylene. The invention also affords dissolution inacetone, acetonitrile, dimethylformamide, N-methylpyrrolidone,dimethylacetamide, hexamethylphosphorotriamide, dimethylsulfoxide,sulfolane, methanol, ethanol and isopropanol.

The temperature at which the process is effected can be important. Infact, a salt-sequestering agent complex may be insoluble when cold inthe solvent used, but soluble when warm or hot. On the other hand, thetemperature used will of course be limited by the boiling point of thesolvent employed. Generally speaking, the temperature may vary withinbroad limits; more particularly, the temperature is generally betweenabout -50° and about 250° C.

The pressure under which the process is carried out is not critical. Itis possible to operate at atmospheric pressure, or a pressure above orbelow atmospheric pressure.

The sequestering agent is generally used in amounts such that the molarratio of the sequestering agent to the salt to be solubilized is betweenabout 0.001 and about 50. Generally, the greaeter the amount of thesequestering agent, the more complexing will take place and the moreextensive the resulting dissolution will be. However, above a ratio of50, the increase in solubility is no longer significant.

The process according to the invention may be applied to a large numberof fields of industrial chemistry.

It will be obvious to those skilled in the art that the dissolutionobtained according to the process of the invention makes it possible toreact the salt under consideration with a substrate in solvents whereinsuch a reaction has not heretofore been possible, which will be of greatinterest in numerous cases of organic synthesis. This is the case of thefirst variation discussed hereinabove.

Another interesting application concerns the extraction of metals. Ametallic compound A⁻ M⁺ may be extracted from a solution by making itpass, by means of complex formation according to the invention, from anorganic or aqueous phase into another organic phase. This is the case ofthe second variant discussed hereinabove. For example, it is possible inthis manner to extract from an aqueous solution of picrates of alkaliand alkaline earth metals, as well as Ag picrate, using a sequesteringagent according to the invention in methylene chloride. Alkali metalthiocyanates may be similarly extracted.

The present invention also concerns as novel products, the complexes ofthe formula:

    [N--[CHR.sub.1 --CHR.sub.2 --O--(CHR.sub.3 --CHR.sub.4 --O--).sub.n R.sub.5 ].sub.3 ].sub.y (M.sup.+ A.sup.-)                         (II)

wherein R₁, R₂, R₃, R₄, R₅, n, M⁺, A⁻ and y are defined generally andpreferentially as hereinabove, which are formed in the process of theinvention.

Even more partcularly, the invention concerns the following complexes:

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.3).sub.3 ].sub.y (A.sup.- M.sup.+)

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.3).sub.3 ].sub.y (A.sup.- M.sup.+)

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.2 H.sub.5).sub.3 ].sub.y (A.sup.- M.sup.+)

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.2 H.sub.5).sub.3 ].sub.y (A.sup.- M.sup.+)

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.3 H.sub.7).sub.3 ].sub.y (A.sup.- M.sup.+)

    [N--[CH.sub.2 --CH.sub.2 --O--(CH.sub.2 --CH.sub.2 --O).sub.3 --CH.sub.3 ].sub.3 ].sub.y (M.sup.+ A.sup.-)

    [N--[CH.sub.2 --CH.sub.2 --O--(CH.sub.2 --CH.sub.2 --O).sub.5 --CH.sub.3 ].sub.3 ].sub.y (M.sup.+ A.sup.-)

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.3 H.sub.7).sub.3 ].sub.y (A.sup.- M.sup.+)

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.4 H.sub.9).sub.3 ].sub.y (A.sup.- M.sup.+)

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.4 H.sub.9).sub.3 ].sub.y (A.sup.- M.sup.+)

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.3).sub.3 ].sub.y (A.sup.- M.sup.+)

    [N--(CH.sub.2 --CH.sub.2 --O--CHCH.sub.3 --CH.sub.2 --O--CH.sub.3).sub.3 ].sub.y (A.sup.- M.sup.+)

    [N--(CH.sub.2 --CHCH.sub.3 --O--CHCH.sub.3 --CH.sub.2 --O--CH.sub.3).sub.3 ].sub.y (A.sup.- M.sup.+)

wherein A⁻, M⁺ and y are defined as above.

The sequestering agent used in the process according to the inventioncan be prepared by the condensation of a salt of the formula: ##STR37##wherein R₃, R₄, R₅ and n have their previously defined meanings, andwherein M represents an alkali metal atom chosen from among sodium,potassium and lithium, either with an amine of the general formula:##STR38## wherein R₁ and R₂ have the significance indicated hereinaboveand X represents chlorine or bromine, or with the correspondinghydrochloride or hydrobromide.

The molar ratio of the alkali metal salt to the amine is betweenapproximately 3 and approximately 5.

The condensation reaction is effected at a temperature of between about100° and about 150° C., for a period of time of from about 1 to about 15hours, and in the presence of a suitable solvent, for example,chlorobenzene or, preferably, a monoalkyether of ethylene glycol of theformula R₅ --(O--CHR₄ --CHR₃)_(n) --OH wherein R₃, R₄, R₅ and n aredefined as before.

The reaction is preferably carried out so that a solution containing 2to 5 moles of the alkali metal salt is present per liter of the solvent.

The mixture at the end of the reaction contains principally a tertiaryamine of the formula: ##STR39## but also contains, in a small amount, asecondary amine of the formula: ##STR40## and traces of a primary amineof the formula: ##STR41## The tertiary, secondary and primary amines aregenerally obtained in a ratio of approximately 90:8:2, respectively,after distillation.

The mixture obtained after the first distillation, i.e. containing thethree types of amines, may be used directly in the process of theinvention. However, in a preferred embodiment of the invention, a morestringent distillation of the mixture is effected in order to obtain anessentially pure tertiary amine.

Other characteristics and advantages of the invention will appear fromthe examples which follow hereafter. These examples are set forth merelyfor purposes of illustration and are not to be considered as limitingthe range of the present invention.

In the examples, the solubilities measured and the calculated maximumsolubilities are expressed in terms of the metal content in thesolution. The maximum calculated solubility corresponds to the casewherein all of the salt involved passes into solution. The proportiondissolved represents the ratio of the measured solubility to the maximumcalculated solubility, i.e. it expresses the proportion of the complexedsalt passing into solution. The formulas of complexes given are those ofthe complexes passing into solution in the solvent under consideration.

EXAMPLE 1 Direct Solubilization of Tungsten Hexachloride in MethyleneChloride

In a 50 ml Erlenmeyer flask equipped with an ascending cooler and amagnetic agitator, 20 ml of anhydrous, purified methylene chloride (i.e.without stabilizer) are introduced. Subsequently, 0.4 g of tungstenhexachloride (0.001 mole) and 0.32 g of tris(3,6-dioxaheptyl)amine(0.001 mole) are added.

The mixture is agitated for 10 minutes at ambient temperature, then iscentrifuged. The clear solution obtained in this manner is analyzed byflame spectrometry.

Measured solubility: 9290 mg/l.

Maximum calculated solubility: 9295 mg/l.

Proportion dissolved: 99%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ ](WCl₆).

Comparative experiment. The operation is performed as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Measured solubility: 500 mg/l.

EXAMPLE 2 Direct Solubilization of Iridium Trichloride in MethyleneChloride

The operation is performed according to the procedure of Experiment 1,but using the following reagents:

IrCl₃ =0.297 g (0.001 mole)

tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Measured solubility: 9500 mg/l.

Maximum calculated solubility: 9580 mg/l.

Proportion dissolved: 99%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ ] (IrCl₃).

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Measured solubility: less than 1 mg/l.

EXAMPLE 3 Direct Solubilization of Rhenium Trichloride in MethyleneChloride

The operation is performed according to the procedure of Example 1, butusing the following reagents:

ReCl₃ =0.292 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Measured solubility: 9300 mg/l.

Maximum calculated solubility: 9310 mg/l.

Proportion dissolved: 99%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ ] (ReCl₃).

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Measured solubility: less than 1 mg/l.

EXAMPLE 4 Direct Solubilization of Ruthenium Trichloride in MethyleneChloride

The operation is effected as in Example 1, but using the followingreagents:

RuCl₃ =0.207 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Measured solubility: 5000 mg/l.

Maximum calculated solubility: 5050 mg/l.

Proportion dissolved: 99%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ ] (RuCl₃).

Comparative experiment. The operation is carried out as above, butwithout the addition of tris(3,6-dioxaheptyl)amine.

Measured solubility: less than 1 mg/l.

EXAMPLE 5 Direct Solubilization of Molybdenum Pentachloride in MethyleneChloride

The operation is performed as in Example 1, but using the followingreagents:

MoCl₅ =0.273 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³

Measured solubility: 4250 mg/l.

Maximum calculated solubility: 4800 mg/l.

Proportion dissolved: 88%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ ] (MoCl₅).

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Measured solubility: 1360 mg/l.

EXAMPLE 6 Direct Solubilization of Rhodium Trichloride in MethyleneChloride

The operation is effected as in Example 1, but using the followingreagents:

RhCl₃ =0.209 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Measured solubility: 5100 mg/l.

Maximum calculated solubility: 5150 mg/l.

Proportion dissolved: 99%.

Complex formed. [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ ] (RhCl₃)

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Measured solubility: less than 2 mg/l.

EXAMPLE 7 Direct Solubilization of Palladium Chloride in MethyleneChloride

The operation is performed as in Example 1, but using the followingreagents:

PdCl₂ =0.177 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ CH₂ =20 cm³.

Measured solubility: 2600 mg/l.

Maximum calculated solubility: 5320 mg/l.

Proportion dissolved: 49%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: less than 2 mg/l.

EXAMPLE 8 Direct Solubilization of Platinum Chloride in MethyleneChloride

The operation is performed as in Example 1, but using the followingreagents:

PtCl₂ =0.266 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Measured solubility: 9700 mg/l.

Maximum calculated solubility: 9755 mg/l.

Proportion dissolved: 99%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ ] (PtCl₂).

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Measured solubility: less than 1 mg/l.

EXAMPLE 9 Direct Solubilization of Tantalum Pentafluoride in MethyleneChloride

The operation is performed as in Example 1, but using the followingreagents:

TaF₅ =0.276 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Measured solubility: 2420 mg/l.

Maximum calculated solubility: 9050 mg/l.

Proportion dissolved: 26%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 10 Direct Solubilization of Iron Chloride (Ferrous) in MethyleneChloride

The operation is performed as in Example 1, but using the followingreagents:

FeCl₂.4 H₂ O=0.199 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Measured solubility: 950 mg/l.

Maximum calculated solubility: 2794 mg/l.

Proportion dissolved: 34%.

Comparative experiment. The experiment is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: 2 mg/l.

EXAMPLE 11 Direct Solubilization of Molybdenum Hexacarbonyl in MethyleneChloride

The operation is performed as in Example 1, but using the followingreagents:

Mo(CO)₆ =0.276 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Measured solubility: 4780 mg/l.

Maximum calculated solubility: 4797 mg/l.

Proportion dissolved: 99%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 12 Direct Solubilization of Titanium Chloride in MethyleneChloride

The operation is performed as in Example 1, but using the followingreagents:

TiCl₃ =0.157 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Measured solubility: 2390 mg/l.

Maximum calculated solubility: 2395 mg/l.

Proportion dissolved: 99%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ ] (TiCl₃).

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 13 Direct Solubilization of Magnesium Perchlorate in MethyleneChloride

The operation is performed as in Example 1, but using the followingreagents:

Mg(ClO₄)₂.H₂ O=0.223 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Measured solubility: 14 mg/l.

Maximum calculated solubility: 1215 mg/l.

Proportion dissolved: 1%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Measured solubility: less than 0.4 mg/l.

EXAMPLE 14 Direct Solubilization of Selected Zinc Salts in MethyleneChloride

The operation is performed as in Example 1, but using the followingreagents:

(a)

ZnCl₂ =0.136 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Measured solubility: 2190 mg/l.

Maximum calculated solubility: 3270 mg/l.

Proportion dissolved: 67%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: less than 1 mg/l.

(b)

Zn(NO₃).6 H₂ O=0.297 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Solubility measured: 81 mg/l.

Maximum solubility calculated: 3270 mg/l.

Proportion dissolved: 2%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 15 Direct Solubilization of Selected Nickel Salts in MethyleneChloride

The operation is performed as in Example 1, but using the followingreagents:

(a)

NiCl₂.6 H₂ O=0.238 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Measured solubility: 800 mg/l.

Maximum calculated solubility: 2935 mg/l.

Proportion dissolved: 27%.

Comparative experiment: The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: less than 1 mg/l.

(b)

(CH₃ COO)₂ Ni.4 H₂ O=0.249 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Solubility measured: 250 mg/l.

Maximum calculated solubility: 2935 mg/l.

Proportion dissolved: 8.5%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 16 Direct Solubilization of Selected Cobalt Salts in MethyleneChloride

The operation is performed as in Example 1, but using the followingreagents:

(a)

CoCl₂.6 H₂ O=0.238 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Solubility measured: 1100 mg/l.

Maximum calculated solubility: 2950 mg/l.

Proportion dissolved: 37%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: less than 1 mg/l.

(b)

CoBr₂.2 H₂ O=0.255 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³

Solubility measured: 800 mg/l.

Maximum calculated solubility: 2950 mg/l.

Proportion dissolved: 27%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: less than 1 mg/l.

(c)

(CH₃ COO)₂ Co.4 H₂ O=0.242 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Solubility measured: 150 mg/l.

Maximum calculated solubility: 2950 mg/l.

Proportion dissolved: 5%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: 5 mg/l.

EXAMPLE 17 Direct Solubilization of Chromium Acetate in MethyleneChloride

The operation is performed as in Example 1, but using the followingreagents:

(CH₃ COO)₃ Cr=0.229 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =20 cm³.

Solubility measured: 67 mg/l.

Maximum calculated solubility: 2600 mg/l.

Proportion dissolved: 2%.

Comparative experiment. The operation is effected as above, but withouttris(3,6-dioxaheptyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 18 Direct Solubilization of Mercury Chloride in MethyleneChloride

Two experiments are performed using the procedure of Example 1, butdiffering in the nature of the sequestering agent employed.

Experiment 1

HgCl=0.236 g (0.001 mole).

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole).

CH₂ Cl₂ =20 cm³.

Solubility measured: 1200 mg/l.

Maximum calculated solubility: 10020 mg/l.

Proportion dissolved: 12%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: 33 mg/l.

Experiment 2

HgCl=0.236 g (0.001 mole).

Tris(3,6,9-trioxadecyl)amine=0.455 g (0.001 mole).

CH₂ Cl₂ =20 cm³.

Solubility measured: 9300 mg/l.

Maximum calculated solubility: 10020 mg/l.

Proportion dissolved: 93%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ ](HgCl).

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6,9-trioxadecyl)amine.

Solubility measured: 30 mg/l.

Thus, it has been found that the solubility of mercury chlorideincreases with the number of oxygen atoms contained in the molecule ofthe sequestering agent.

EXAMPLE 19 Direct Solubilization of Mercury Nitrate in MethyleneChloride

Two experiments are performed using the procedure of Example 1, butdiffering in the nature of the sequestering agent employed.

Experiment 1

HgNO₃.H₂ O=0.281 g (0.001 mole).

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole).

CH₂ Cl₂ =20 cm³.

Solubility measured: 600 mg/l.

Maximum calculated solubility: 10020 mg/l.

Proportion dissolved: 6%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: 33 mg/l.

Experiment 2

HgNO₃.H₂ O=0.281 g (0.001 mole).

Tris(3,6,9-trioxadecyl)amine=0.455 g (0.001 mole).

CH₂ Cl₂ =20 cm³.

Solubility measured: 1200 mg/l.

Maximum calculated solubility: 10020 mg/l.

Proportion dissolved: 12%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6,9-trioxadecyl)amine.

Solubility measured: 30 mg/l.

Here again, it has been found that solubility increases with the numberof oxygen atoms contained in the molecule of the sequestering agent.

EXAMPLE 20 Direct Solubilization of Calcium Chloride in MethyleneChloride

The operation is performed generally as in Example 1, except that themixture is agitated for a few minutes and then allowed to decantovernight, using the following reagents:

CaCl₂ =0.111 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =10 cm³.

Solubility measured: 2000 mg/l.

Maximum calculated solubility: 4000 mg/l.

Proportion dissolved: 50%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 21 Direct Solubilization of Copper Thiocyanate in MethyleneChloride

The operation is performed as in Example 1, except that the mixture isagitated for a few minutes and then allowed to decant overnight, usingthe following reagents:

CuSCN=0.122 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =10 cm³.

Solubility measured: 140 mg/l.

Maximum calculated solubility: 6355 mg/l.

Proportion dissolved: 2%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 22 Direct Solubilization of Mercury Thiocyanate in MethyleneChloride

The operation is performed as in Example 1, except that the mixture isagitated for a few minutes and then allowed to decant overnight, usingthe following reagents:

Hg(SCN)₂ =0.316 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =10 cm³.

Solubility measured: 20,000 mg/l.

Maximum calculated solubility: 20060 mg/l.

Proportion dissolved: 99%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ ]Hg(SCN)₂.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: less than 10 mg/l.

EXAMPLE 23 Direct Solubilization of Tungsten Hexachloride in Toluene

Into a 50 ml Erlenmeyer flask, equipped with an ascending cooler and amagnetic agitator, are introduced 20 ml of toluene. Then, 0.4 g oftungsten hexachloride (0.001 mole) and 0.365 g tris(3,6-dioxaoctyl)amine(0.001 mole) are added.

The mixture is agitated for 10 minutes at ambient temperature, then iscentrifuged. The clear solution obtained in this manner is analyzed byflame spectrometry.

Solubility measured: 7500 mg/l.

Maximum calculated solubility: 9295 mg/l.

Proportion dissolved: 80%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₂ H₅)₃ ](WCl₆).

Comparative experiment: The operation is effected as above, but withoutthe addition of tris(3,6-dioxaoctyl)amine.

Solubility measured: 200 mg/l.

EXAMPLE 24 Direct Solubilization of Iridium Trichloride in Toluene

The operation is performed as in Example 23, but using the followingreagents:

IrCl₃ =0.297 g (0.001 mole)

Tris(3,6-dioxaoctyl)amine=0.365 g (0.001 mole)

Toluene=20 cm³.

Solubility measured: 2060 mg/l.

Maximum calculated solubility: 9580 mg/l.

Proportion dissolved: 20%

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaoctyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 25 Direct Solubilization of Rhenium Trichloride in Toluene

The operation is performed as in Example 23, but using the followingreagents:

ReCl₃ =0.292 g (0.001 mole)

Tris(3,6-dioxaoctyl)amine=0.365 g (0.001 mole)

Toluene=20 cm³.

Measured solubility: 2090 mg/l.

Maximum calculated solubility: 9310 mg/l.

Proportion dissolved: 22%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaoctyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 26 Direct Solubilization of Ruthenium Trichloride in Toluene

The operation is performed as in Example 23, but using the followingreagents:

RuCl₃ =0.207 g (0.001 mole)

Tris(3,6-dioxaoctyl)amine=0.365 g (0.001 mole)

Toluene=20 cm³.

Solubility measured: 1600 mg/l.

Maximum calculated solubility: 5050 mg/l.

Proportion dissolved: 32%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--C₂ H₅)₃ ](RuCl₃).

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaoctyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 27 Direct Solubilization of Molybdenum Pentachloride in Toluene

The operation is performed as in Example 23, but using the followingreagents:

MoCl₅ =0.273 g (0.001 mole)

Tris(3,6-dioxaoctyl)amine=0.365 g (0.001 mole)

Toluene=20 cm³.

Solubility measured: 80 mg/l.

Maximum calculated solubility: 4800 mg/l.

Proportion dissolved: 2%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaoctyl)amine.

Solubility measured: 10 mg/l.

EXAMPLE 28 Direct Solubilization of Rhodium Trichloride in Toluene

The operation is performed as in Example 23, but using the followingreagents:

RhCl₃ =0.209 g (0.001 mole)

Tris(3,6-dioxaoctyl)amine=0.365 g (0.001 mole)

Toluene=20 cm³.

Solubility measured: 683 mg/l.

Maximum calculated solubility: 5150 mg/l.

Proportion dissolved: 13%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaoctyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 29 Direct Solubilization of Platinum Chloride in Toluene

The operation is performed as in Example 23, but using the followingreagents:

PtCl₂ =0.266 g (0.001 mole)

Tris(3,6-dioxaoctyl)amine=0.365 g (0.001 mole)

Toluene=20 cm³.

Solubility measured: 9700 mg/l.

Maximum calculated solubility: 9755 mg/l.

Proportion dissolved: 99%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--C₂ H₅)₃ ](PtCl₂).

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaoctyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 30 Direct Solubilization of Ruthenium Trichloride in Cyclohexane

Into a 50 ml Erlenmeyer flask, equipped with an ascending cooler and amagnetic agitator, are introduced 20 ml of cyclohexane. Then, 0.207 g ofruthenium trichloride (0.001 mole) and 0.365 g oftris(3,6-dioxaoctyl)amine (0.001 mole) are added.

The mixture is agitated for 10 minutes at ambient temperature, then iscentrifuged. The clear solution obtained in this manner is analyzed byflame spectrometry.

Solubility measured: 110 mg/l.

Maximum calculated solubility: 5050 mg/l.

Proportion dissolved: 2%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--C₂ H₅)₃ ](RuCl₃).

Comparative experiment. The operation is carried out as above, withoutthe addition of tris(3,6-dioxaoctyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 31 Direct Solubilization of Iridium Trichloride in Cyclohexane

The operation is performed as in Example 30, but using the followingreagents:

IrCl₃ =0.299 g (0.001 mole)

Tris(3,6-dioxaoctyl)amine=0.365 g (0.001 mole)

Cyclohexane=20 cm³.

Solubility measured: 4700 mg/l.

Maximum calculated solubility: 9610 mg/l.

Proportion dissolved: 50%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--C₂ H₅)₃ ](IrCl₃).

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaoctyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 32 Direct Solubilization of Platinum Chloride in Cyclohexane

The operation is performed as in Example 30, but using the followingreagents:

PtCl₂ =0.266 g (0.001 mole)

Tris(3,6-dioxaoctyl)amine=0.365 g (0.001 mole)

Cyclohexane=20 cm³.

Solubility measured: 1500 mg/l.

Maximum calculated solubility: 9755 mg/l.

Proportion dissolved: 15%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--C₂ H₅)₃ ](PtCl₂).

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaoctyl)amine.

Solubility measured: less than 1 mg/l.

EXAMPLE 33 Direct Solubilization of Rhodium Trichloride in Cyclohexane

The operation is performed as in Example 30, but using the followingreagents:

RhCl₃ =0.209 g (0.001 mole)

Tris(3,6-dioxaoctyl)amine=0.365 g (0.001 mole)

Cyclohexane=20 cm³.

Solubility measured: 20 mg/l.

Maximum calculated solubility: 5150 mg/l.

Proportion dissolved: 0.4%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaoctyl)amine.

Solubility measured: less tham 1 mg/l.

EXAMPLE 34 Direct Solubilization of Cadmium Iodide in Methylene Chloride

The operation is performed as in Example 1, but using the followingreagents:

CdI₂ =0.366 g (0.001 mole)

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole)

CH₂ Cl₂ =10 cm³.

Solubility measured: 9500 mg/l.

Maximum calculated solubility: 11240 mg/l.

Proportion dissolved: 85%.

Complex formed: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ ](CdI₂).

Comparative Experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: less tham 0.5 mg/l.

EXAMPLE 35 Effect of the Size of the Cation on the Degree ofSolubilization in Methylene Chloride

Three experiments are performed as in Example 1, except that the mixtureis agitated for several minutes and then allowed to decant overnight,using the following reagents:

Experiment 1

LiSCN=0.065 g (0.001 mole).

Tris(3,6-dioxaheptyl)amine=0.323 g (0.001 mole).

CH₂ Cl₂ =10 cm³.

Experiment 2

NaSCN=0.080 g (0.001 mole).

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole).

CH₂ Cl₂ =10 cm³.

Experiment 3

KSCN=0.097 g (0.001 mole).

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole).

CH₂ Cl₂ =10 cm³.

Three comparative experiments also are effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

The results obtained are given in Table I hereinbelow. The complexesformed are:

Experiment 1: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ ](LiSCN)

Experiment 2: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ ](NaSCN)

Experiment 3: [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ ](KSCN).

The proportions dissolved are as follows:

Experiment 1: 98%

Experiment 2: 82%

Experiment 3: 79%.

                  TABLE I                                                         ______________________________________                                                 With tris      Without tris                                                   (3,6-dioxaheptyl)amine                                                                       (3,6-dioxaheptyl)                                                              Maximum  amine                                       Experi-        Solubility                                                                              Calculated                                                                             Solubility                                  ment  Salt     Measured  Solubility                                                                             Measured                                    ______________________________________                                        1     LiSCN      680 mg/l                                                                                694 mg/l                                                                             < 1 mg/l                                    2     NaSCN    1,800 mg/l                                                                              2,300 mg/l                                                                             < 1 mg/l                                    3     K SCN    3,100 mg/l                                                                              3,910 mg/l                                                                             < 1 mg/l                                    ______________________________________                                    

EXAMPLE 36 Effect of Temperature on the Degree of Solubilization ofLithium Thiocyanate in Toluene

10 cm³ of a 0.1 M tris(3,6-dioxaheptyl)amine solution in toluene areagitated at ambient temperature with 1.1 millimole of powdered lithiumthiocyanate.

After decanting the solution, the toluene phase is analyzed. It isdetermined by infrared analysis that the tris(3,6-dioxaheptyl)amine hasalmost totally disappeared from the solution. This may be explained bythe formation of the complex:

    (LiSCN)[tris(3,6-dioxaheptyl)amine]

which has a very low solubility in toluene at ambient temperature.

The above procedure is repeated, except that the mixture is agitated 60°C. The solution becomes clear and infrared analysis shows that all ofthe above-mentioned complex is found in the toluene phase.

EXAMPLE 37 Indirect Solubilization of Ammonium Thiocyanate

0.455 g (0.001 mole) of tris(3,6,9-trioxadecyl)amine is dissolved in 10ml of anhydrous methanol, then 0.076 g (0.001 mole) of ammoniumthiocyanate is introduced. The mixture is agitated for 1 hour at ambienttemperature. The methanol is then slowly evaporated and the mixtureobtained is taken up in 20 cm³ of methylene chloride. The solution isfiltered and the solvent is evaporated. An orange colored liquid complexis obtained having a sulfur content of 4.8%. (The maximum calculatedcontent is 6.03%).

The complex corresponds to the formula:

    [N(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.3).sub.3 ](NH.sub.4 SCN).

EXAMPLE 38 Indirect Solubilization of Lithium Chloride in VariousSolvents

1.6 of tris(3,6-dioxaheptyl)amine (0.005 mole) is dissolved in 30 ml ofanhydrous methanol. Into the solution thus obtained, 0.22 g (0.005 mole)of anhydrous lithium chloride is introduced. The mixture is agitated for1 hour at ambient temperature. The methanol is then slowly evaporatedand the mixture obtained is taken up in 20 cm³ methylene chloride. Thesolution is filtered and the solvent is evaporated. An orange coloredliquid is obtained, which is the lithiumchloride-tris(3,6-dioxaheptyl)amine complex having lithium and chloridecontents as follows:

Li⁺ : 1.7% (theoretical: 1.91%)

Cl⁻ : 8.6% (theoretical: 9.71%)

and a formula of [N(CH₂ --CH₂ --O--CH₂ --CH₂ --O--CH₃)₃ ](LiCl).

The orange colored liquid is particularly soluble in chlorobenzene,chloroform and dimethylsulfoxide.

EXAMPLE 39 Indirect Solubilization of Lithium Chloride

0.455 g (0.001 mole) of tris(3,6,9-trioxadecyl)amine is dissolved in 10ml of anhydrous methanol and 0.042 g (0.001 mole) of dehydrated lithiumchloride is then introduced. The mixture is agitated for 1 hour atambient temperature. The methanol is then slowly evaporated and themixture thus obtained is taken up in 20 cm² of methylene chloride. Thesolution is filtered and the solvent is evaporated. An orange coloredliquid is obtained, representing the complex:

    [N(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.3).sub.3 ](LiCl)

having the following lithium and chlorine contents:

Li⁺ : 1.03% (theoretical: 1.41%)

Cl⁻ : 5.3% (theoretical: 7.16%).

This complex is soluble in chlorobenzene, dimethylsulfoxide,N-methylpyrrolidone, and chloroform.

EXAMPLE 40 Effect of the Sequestering Agent Content on the Rate ofExtraction of Cesium Picrate

An aqueous solution containing 0.1 mole/l of cesium hydroxide and 0.0015mole/l of picric acid is prepared.

A solution in methylene chloride of 0.007 mole/l oftris(3,6-dioxaheptyl)amine and a solution of 0.007 mole/l oftris(3,6,9-trioxadecyl)amine in methylene chloride are also prepared.

Equal volumes of each of the solutions of the sequestering agents aremixed with the cesium picrate solution.

In the case of tris(3,6-dioxaheptyl)amine, an extraction of 22% ofcesium picrate is observed.

In the case of tris(3,6,9-trioxadecyl)amine, an extraction of 60% isobtained.

A comparative experiment without sequestering agent gives no extraction.

EXAMPLE 41 Effect of the Sequestering Agent Content on the Rate ofExtraction of Sodium Picrate

The operation is as follows: An aqueous solution A containing 1 mole/lof sodium hydroxide and 0.00021 mole/l of picric acid is prepared.Similarly, nine solutions B of sequestering agents according to theinvention, in methylene chloride, are prepared by varying the nature ofthe sequestering agent and its concentration.

Nine experiments are then executed by mixing equal volumes of solutionsA and B and measuring the percentage of sodium picrate extracted, i.e.the percent passing from the aqueous phase into the methylene chloridephase.

The results obtained are given in Table II below.

                  TABLE II                                                        ______________________________________                                                               Concentration                                                                 of the Seques-                                                                            Sodium                                     Experi-                tering Agent                                                                              Picrate                                    ment  Sequestering Agent                                                                             mole/l      Extracted                                  ______________________________________                                        1     tris(3,6-dioxaheptyl)amine                                                                     8.85 × 10.sup.-5                                                                    28%                                        2     "                2.62 × 10.sup.-4                                                                    51%                                        3     "                2.6 × 10.sup.-3                                                                     92.5%                                      4     tris(3,6-dioxaoctyl)amine                                                                      8.08 × 10.sup.-5                                                                    11%                                        5     "                2.33 × 10.sup.-4                                                                    17%                                        6     "                2.33 × 10.sup.-3                                                                    54%                                        7     tris(3,6-dioxadecyl)amine                                                                      7.01 × 10.sup.-5                                                                    8%                                         8     "                2 × 10.sup.-4                                                                       12.5%                                      9     "                2 × 10.sup.-3                                                                       42.5%                                      ______________________________________                                    

It has been found that the amount extracted increases with the amount ofsequestering agent used.

A comparative experiment without the addition of a sequestering agent iseffected; the percent of sodium picrate extracted is zero.

EXAMPLE 42 Effect of the Nature of the Sequestering Agent on the Rate ofExtraction

The operation is as follows: An aqueous solution A containing 0.1 mole/lof sodium hydroxide and 0.0007 mole/l of picric acid is prepared. Thesolution is agitated for 3 hours. In the same manner, two othersolutions A are prepared by replacing sodium hydroxide with potassiumhydroxide in the one case and cesium hydroxide in the other.

Two solutions B are then prepared, one with 0.0007 mole/ltris(3,6-dioxaheptyl)amine in methylene chloride, the other with thesame amount of tris(3,6,9-trioxadecyl)amine in methylene chloride.

Six experiments are performed by mixing intimately for 1 minute equalvolumes of each of the three solutions A with each of the two solutionsB and by measuring after decantation the percentage of the picrateextracted, i.e. the percent passing from the aqueous phase into themethylene chloride phase.

The results obtained are given in Table III.

                  TABLE III                                                       ______________________________________                                        Salt to be                                                                            Tris(3,6-dioxaheptyl)-                                                                         Tris(3,6,9-trioxadecyl)-                             extracted                                                                             amine            amine                                                ______________________________________                                        Experiment                                                                    1 and 2                                                                       Pi.sup.- Na.sup.+                                                                     23%              13%                                                  Experiment                                                                    3 and 4                                                                       Pi.sup.- K.sup.+                                                                      18%              29%                                                  Experiment                                                                    5 and 6                                                                       Pi.sup.- Cs.sup.+                                                                      7%              19%                                                  ______________________________________                                    

In a similar manner, three comparative experiments are effected bymixing the four solutions A with equal volumes of methylene chloridecontaining no sequestering agent: the extraction percentages of thedifferent picrates are zero.

EXAMPLE 43 Extraction of Barium Picrate in Aqueous Solution

The operation is performed as follows: An aqueous solution A containing0.1 mole/l of barium hydroxide and 0.014 mole/l of picric acid isprepared. The solution is agitated for 3 hours. Two solutions B are alsoprepared, one containing 0.007 mole/l of tris(3,6-dioxaheptyl)amine, theother 0.007 mole/l of tris(3,6,9-trioxadecyl)amine, in methylenechloride.

Equal volumes of solution A and each of the solutions B are mixedintimately for 1 minute. The percentage of the picrate extracted ismeasured after decantation (i.e. the percent of picrate passing from theaqueous phase into the methylene chloride phase).

With tris(3,6-dioxaheptyl)amine, 75.5% barium picrate is extracted; withtris(3,6,9-trioxadecyl)amine the proportion is 77.5%.

Without the sequestering agent, the percent of extraction is zero.

EXAMPLE 44 Direct Solubilization of Lead Thiocyanate in Methanol and inAcetonitrile

Two experiments are performed as in Example 1, except that the mixtureis agitated for a few minutes and allowed to decant overnight, using thereagents indicated below:

Experiment 1

Pb(SCN)₂ =0.323 g (0.001 mole).

Tris(3,6,9-trioxadecyl)amine=0.455 g (0.001 mole).

Methanol=10 cm³.

Solubility measured: 12900 mg/l.

Maximum calculated solubility: 20720 mg/l.

Proportion dissolved: 62%.

Comparative example. The operation is effected as above, but without theaddition of tris(3,6,9-trioxadecyl)amine.

Solubility measured: 250 mg/l.

Experiment 2

Pb(SCN)₂ =0.323 g (0.001 mole).

Tris(3,6,9-trioxadecyl)amine=0.455 g (0.001 mole).

Acetonitrile=10 cm³.

Solubility measured: 500 mg/l.

Maximum solubility calculated: 20720 mg/l.

Proportion dissolved: 2%.

After a decantation of 3 days, the following results are obtained:

Solubility measured: 2800 mg/l

Proportion dissolved: 13.5%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6,9-trioxadecyl)amine.

Solubility measured: less tham 10 mg/l.

EXAMPLE 45 Direct Solubilization of Lead Acetate in Acetonitrile andMethylene Chloride

Two experiments are performed as in Example 1, except that the mixtureis agitated for a few minutes and the allowed to decant overnight, usingthe reagents indicated below:

Experiment 1

(CH₃ COO)₂ Pb=0.325 g (0.001 mole).

Tris(3,6,9-trioxadecyl)amine=0.455 g (0.001 mole).

Acetonitrile=10 cm³.

Solubility measured: 7750 mg/l.

Maximum solubility calculated: 20720 mg/l.

Proportion dissolved: 37.5%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6,9-trioxadecyl)amine.

Solubility measured: 65 mg/l.

Experiment 2

(CH₃ COO)₂ Pb=0.325 g (0.001 mole).

Tris(3,6-dioxaheptyl)amine=0.32 g (0.001 mole).

Methylene chloride=10 cm³.

Solubility measured: 2000 mg/l.

Maximum calculated solubility: 20720 mg/l.

Proportion dissolved: 10%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3,6-dioxaheptyl)amine.

Solubility measured: less than 15 mg/l.

Examples 46 to 51 below describe the preparation of representativesequestering agents of the invention, namely tris(3,6-dioxaheptyl)amine,tris(3,6,9-trioxadecyl)amine, tris(3,6-dioxadecyl)amine,tris[3-oxabutyl]amine, tris(3,6,9,12-tetraoxatridecyl)amine andtris(3,6,9,12,15,18-hexaoxanonadecyl)amine. All of the othersequestering agents envisioned by the present invention may be preparedby similar processes.

EXAMPLE 46 Preparation of Tris(3,6-dioxaheptyl)amine (a) Preparation ofsodium 2-methoxyethanolate

Into a one liter three-necked flask, equipped with a mechanicalagitator, a thermometer, and a cooler, 380 g of 2-methoxyethanol (5moles) are introduced. 23 g of sodium (1 mole) are added over a threehour period, while maintaining the temperature of the mixture at 40° C.

(b) Synthesis of tris(3,6-dioxaheptyl)amine

To the mixture thus obtained, 51.6 g of tris(2-chloroethyl)aminehydrochloride (0.215 mole) are added. The mixture is then heated at thereflux temperature of the 2-methoxyethanol (125° C.) for 12 hours andthen the solvent is removed by distillation under reduced pressure. Theexcess sodium 2-methoxyethanolate is neutralized by the addition of 11.6cm³ aqueous HCl (10 N). The sodium chloride is filtered off and thesolution is distilled.

Tris(3,6-dioxaheptyl)amine distills between 165° C. and 180° C. under apressure of 0.5 mmHg. 49 g of the product are thus obtained,representing a yield of 70%.

EXAMPLE 47 Preparation of tris(3,6-dioxadecyl)amine

Into a 1 liter three-necked flask, equipped as described in Example 1,590 g of 3-oxaheptan-1-ol (i.e., the butyl monoether of ethylene glycol)are introduced. 40 g of sodium hydroxide in pellet form are added andthe mixture is heated to 120° C. Sodium 3-oxaheptan-1-olate and waterare formed, with the latter being removed by distillation.

When all of the water of the reaction has been eliminated, 55 g oftris(2-chloroethyl)amine hydrochloride are introduced. The mixture isheated at 130° C. for 5 hours, then cooled. Excess sodium alcoholate isthen neutralized with a 10% aqueous solution of hydrochloric acid. The3-oxaheptan-1-ol is removed by distillation and the sodium chloride isremoved by filtration. The desired product, tris(3,6-dioxadecyl)amine,is distilled (192° C. under 0.1 mmHg).

EXAMPLE 48 Preparation of Tris(3,6,9-trioxadecyl)amine

To a three-necked 1 liter flask equipped with a mechanical agitator, acondenser and a thermometer, and containing 600 g of the monomethylether of diethylene glycol (i.e. 3,6-dioxaheptan-1-ol), corresponding to5 moles, 23 g of sodium (1 mole) are introduced in small fractions toform sodium 3,6-dioxaheptan-1-olate.

When the sodium has been completely transformed, 51.8 g oftris(2-chloroethyl)amine hydrochloride (0.215 mole) are added. Themixture is heated at 130° C. for 8 hours under agitation, then is cooledand the excess sodium alcoholate is neutralized by a 10% aqueoushydrochloric acid solution. The 3,6-dioxaheptan-1-ol is eliminated bydistillation at 130° C. under a pressure of 20 mmHg. The mixture thusobtained is filtered to eliminate sodium chloride and the product isthen distilled. In this manner, 83 g of tris(3,6,9-trioxadecyl)amine areobtained, distilling at 189° C. under 0.1 mmHg.

EXAMPLE 49 Preparation of Tris(3-oxabutyl)amine

To a three-necked 1 liter flask equipped with a mechanical agitator, acondenser and a thermometer, and containing 244 g of methanol, 23 g ofsodium are added. A solution of 30 g (0,125 mole) oftris(chloroethyl)amine hydrochloride in 150 g of methanol are added. Themixture is heated at the reflux temperature for 4 hours, then is cooledand the excess methylate is neutralized by 75 g of concentrated HCl. Themethanol is concentrated. The aqueous layer is extracted with 2×100 g ofdichloromethane. After evaporation of dichloromethane, the desiredproduct, tris(3-oxabutyl)amine is distilled. 18 g are obtained(R=75,7%).

EXAMPLE 50 Preparation of Tris(3,6,9,12-tetraoxatridecyl)amine

To a three-necked 3 liters flask equipped with a mechanical agitator, acondenser and a thermometer, and containing 1640 g (10 moles) ofmonomethylether of triethylene glycol 115 g (5 moles) of sodium areintroduced. The resultant suspension is maintained at 80° C. and asolution of 241 g (1 mole) of tris(β chloroethyl)amine hydrochloride in492 g monomethyl ether of triethylene glycol are added.

The mixture is maintained at 120°-130° C. for 12 hours. The main part ofmonomethyl ether of triethylene glycol is eliminated by distillationunder vacuum. The residue is then cooled and 2000 ml of acidifieddichloromethane are added, and the sodium chloride is remoded byfiltration. The monomethyl ether of triethylene glycol and thedichloromethane are eliminated by distillation of the filtrate. Theresultant tertiary amine is purified with a silica column. 437 g ofdesired product are obtained (R=74,7%).

EXAMPLE 51 Preparation of tris(3,6,9,12,15,18-hexaoxanonadecyl)amine

In the apparatus of example 50, 69 g (3 moles) of sodium are dissolvedin 1500 g of monomethyl ether of pentaethylene glycol at 80° C. 120 g(0,5 mole) of tris(β chloroethyl)amine hydrochloride in 600 g ofmonomethyl ether of pentaethylene glycol are added to the resultantsuspension. The mixture is headed a 125°-140° C. for 15 hours, thencooled and the sodium chloride is removed by filtration. The monomethylether of pentaethylene glycol is eliminated by distillation at 300° C.under a pressure of 0,5 mmHg.

The tertiary amine is filtrated and purified with a silica column.

331 g of desired product are obtained (R=78%).

EXAMPLE 52 Effect of the Nature of the Sequestering Agent on the Rate ofExtraction

The operation is a follows: An aqueous solution A containing 1 mole/l ofsodium hydroxyde and 0,005 mole/l of picric acid is prepared. An aqueoussolution A' containing 1 mole/l of potassium hydroxyde and 0,005 mole/lof picric acid is prepared.

Five solutions B are then prepared with five different sequesteringagents (0,005 mole/l) in methylene chloride.

Ten experiments are performed by mixing 10 cm³ of each of the fivesolution B with each of the solutions A and A' and by measuring thepercentage of the sodium and potassium picrate extracted, i.e. thepercent passing from the aqueous phase into the methylene chloridephase. The results are given in Table IV.

                  TABLE IV                                                        ______________________________________                                                                Sodium     Potassium                                                          picrate    picrate                                              Sequestering  extracted  extracted                                  Experiment                                                                              Agent         %          %                                          ______________________________________                                        1-2       tris(3,6 dioxaheptyl)                                                                       40,5       35                                                   amine                                                               3-4       tris(3,6 dioxaoctyl)                                                                        15,5         25,5                                               amine                                                               5-6       tris(3,6,9 trioxa-                                                                          22,5         45,5                                               decyl) amine                                                        7-8       tris(3,6,9,12 tetra-                                                                        25         55                                                   oxatridecyl) amine                                                   9-10     tris(3,6,9,12,15,18                                                                         22         53                                                   hexaoxanonadecyl)                                                             amine                                                               ______________________________________                                    

EXAMPLE 53 Direct Solubilization of Alkaline Thiocyanates in MethyleneChloride

Three experiments are performed as in Example 1 allowing to decantovernight.

Experiment 1

Li SCN=0,065 g (0,001 mole).

Tris(3-oxabutyl)amine=0,191 g (0,001 mole).

CH₂ Cl₂ =10 cm³.

Solubility measured=690 mg/l.

Maximum calculated solubility=694 mg/l.

Proportion dissolved=99,5%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3-oxabutyl)amine

Solubility measured<1 mg/l.

Experiment 2

Na SCN=0,081 g (0,001 mole).

Tris(3-oxabutyl)amine=0,191 g (0,001 mole).

CH₂ Cl₂ -10 cm³.

Solubility measured=2150 mg/l.

Maximum calculated solubility=2300 mg/l.

Proportion dissolved=93.5%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3-oxabutyl)amine.

Solubility measured<1 mg/l.

Experiment 3

KSCN=0,097 g (0,001 mole).

Tris(3-oxabutyl)amine=0,191 g (0,001 mole).

CH₂ Cl₂ =10 cm³.

Solubility measured=490 mg/l.

Maximum calculated solubility=3910 mg/l.

Proportion dissolved=12.5%.

Comparative experiment. The operation is effected as above, but withoutthe addition of tris(3-oxabutyl)amine.

Solubility measured<1 mg/l.

EXAMPLE 54 Direct Solubilization of Iron Chloride in Methylene Chloride

The operation is performed as in Example 1, but using the followingreagents:

FeCl₃ =0,162 g

Tris(3,6,dioxaheptyl)amine=0,32 g.

CH₂ Cl₂ =20 cm³.

Solubility measured=2720 mg/l.

Maximum calculated solubility=2790 mg/l.

Proportion dissolved=97%.

Comparative experiment. The operation is effected as above, but withouttris(3,6 dioxaheptyl)amine.

Solubility measured=1400 mg/l.

EXAMPLE 55 Direct Solubilization of Iron Chloride in 1,2 dichloroethane

The operation is performed as in Example 1, but using the followingreagents:

FeCl₃ =0,162 g

Tris(3,6 dioxaheptyl)amine=0,32 g

C₂ H₄ Cl₂ =20 cm³.

Solubility measured=2700 mg/l.

Maximum calculated solubility=2790 mg/l.

Proportion dissolved=97%.

Comparative experiment. The operation is effected as above, but withouttris(3,6 dioxaheptyl)amine.

Solubility measured=1980 mg/l.

EXAMPLE 56 Direct Solubilization of Antimony Chloride in MethyleneChloride

The operation is performed as in Example 1, but using the followingreagents:

SbCl₃ =0,228 g

Tris(3,6 dioxaheptyl)amine=0,32 g

CH₂ Cl₂ =20 cm³.

Solubility measured=5950 mg/l.

Maximum calculated solubility=6090 mg/l.

Proportion dissolved=98%.

Comparative experiment. The operation is effected as above, but withouttris(3,6 dioxaheptyl)amine.

Solubility measured=5650 mg/l.

EXAMPLE 57 Direct Solubilization of Sodium Methoxyphenate in MethyleneChloride

The operation is performed as in Example 1, but using the followingreagents:

Sodium methoxyphenate=0,146 g

Tris(3,6 dioxaheptyl)amine=0,32 g

CH₂ Cl₂ =20 cm³.

Solubility measured=380 mg/l.

Maximum calculated solubility=1150 mg/l.

Proportion dissolved=33%.

Comparative experiment. The operation is effected as above, but withouttris(3,6 dioxaheptyl)amine.

Solubility measured<10 mg/l.

EXAMPLE 58 Direct Solubilization of Lanthanum Nitrate in MethyleneChloride

Into a 50 ml Erlenmeyer flask, equipped with an ascending cooler and amagnetic agitator, are introduced 20 ml of anhydrous and purifiedmethylene chloride. Then, 0,001 mole of lanthanum nitrate and 0,001 moleof tris(3,6 dioxaheptyl)amine are added.

The mixture is agitated for 1 hour at ambient temperature, then iscentrifuged. The clear solution obtained in this manner is analysed by Xfluorescence.

La (NO₃)₃, 6H₂ O=0.433 g.

Tris(3,6 dioxaheptyl)amine=0.32 g.

CH₂ Cl₂ =20 cm³.

Solubility measured=1440 mg/l.

Maximum calculated solubility=6950 mg/l.

Proportion dissolved=21%.

Comparative experiment. The operation is effected as above, but withouttris(3,6 dioxaheptyl)amine.

Solubility measured=10 mg/l.

EXAMPLE 59 Direct Solubilization of Cerium Nitrate in Methylene Chloride

The operation is performed as in Example 58 but using the followingreagents:

Ce (NO₃)₃, 6H₂ O=0.434 g

Tris(3,6 dioxaheptyl)amine=0.32 g

CH₂ Cl₂ =20 cm³.

Solubility measured=1740 mg/l.

Maximum calculated solubility=7010 mg/l.

Proportion dissolved=25%.

Comparative experiment. The operation is effected as above, but withoutusing tris(3.6 dioxaheptyl)amine.

Solubility measured<10 mg/l.

EXAMPLE 60 Direct Solubilization of Europium Nitrate in MethyleneChloride

The operation is performed as in Example 58 but using the followingreagents:

Eu (NO₃)₃, 6H₂ O=0.446 g

Tris(3,6 dioxaheptyl)amine=0,32 g

CH₂ Cl₂ 20 cm³.

Solubility measured=250 mg/l.

Maximum calculated solubility=7600 mg/l.

Proportion dissolved=3%.

Comparative experiment. The operation is effectued as above, but withouttris(3.6 dioxaheptyl)amine.

Solubility measured=50 mg/l.

EXAMPLE 61 Direct Solubilization of Thorium Nitrate in MethyleneChloride

The operation is performed as in Example 58 but using the followingreagents:

Th (NO₃)₄, 4H₂ O=0,552 g

Tris(3,6 dioxaheptyl)amine=0,32 g

CH₂ Cl₂ =20 cm³.

Solubility measured=5500 mg/l.

Maximum calculated solubility=11.600 mg/l.

Proportion dissolved=47%.

Comparative experiment. The operation is effected as above, but withoutusing tris(3,6 dioxaheptyl)amine.

Solubility measured <10 mg/l.

EXAMPLE 62 Direct Solubilization of Uranyle Nitrate in MethyleneChloride

The operation is performed as in Example 58 but using the followingreagents:

UO₂ (NO₃)₂, 6H₂ O=0,502 g

Tris(3,6 dioxaheptyl)amine=0,32 g

CH₂ Cl₂ =20 cm3.

Solubility measured=6100 mg/l.

Maximum calculated Solubility=11.900 mg/l.

Proportion dissolved=51%.

Comparative experiment. The operation is effectued as above but withoutusing tris(3.6 dioxaheptyl)amine.

Solubility measured <10 mg/l.

While the invention has been described in terms of various preferredembodiments, the skilled artisan will appreciate that variousmodifications, substitutions, omissions, and changes may be made withoutdeparting from the spirit thereof. Accordingly, it is intended that thescope of the present invention be limited solely by the scope of thefollowing claims.

What is claimed is:
 1. A process for solubilizing an organic or mineralsalt in an organic solvent in which the organic or mineral salt isinitially not soluble, or for increasing the solubility of an organic ormineral salt in an organic solvent, said process comprising contactingsaid organic or mineral salt of the formula A⁻ M⁺, wherein A⁻ is amineral or organic anion and M⁺ is a cation selected from the groupconsisting of the cation NH₄ ⁺ and its derivatives, and the cationsderived from the metals of the groups I_(A), II_(A), III_(A), IV_(A),V_(A), VI_(A), VII_(A), VIII, I_(B), II_(B), III_(B), IV_(B) and V_(B)of the periodic table, with at least one sequestering agent, saidsequestering agent being soluble in said organic solvent and having theformula:

    N[CHR.sub.1 --CHR.sub.2 --O--(CHR.sub.3 --CHR.sub.4 --O).sub.n --R.sub.5 ].sub.3                                                   (I)

wherein n is an integer from 0 to 10 inclusive; R₁, R₂, R₃ and R₄, whichcan be the same or different, are each a hydrogen atom or an alkylradical having 1 to 4 carbon atoms; R₅ is a radical selected from thegroup consisting of an alkyl radical having 1 to 12 carbon atoms, acycloalkyl radical having 3 to 12 carbon atoms, a phenyl radical, aradical of the formula ##STR42## and a radical of the formula ##STR43##and m is an integer from 1 to 12 inclusive; said sequestering agent offormula (I) and said organic or mineral salt forming a complex of theformula:

    [N--[CHR.sub.1 --CHR.sub.2 --O--(CHR.sub.3 --CHR.sub.4 --O).sub.n --R.sub.5 ].sub.3 ].sub.y (M.sup.+ A.sup.-)                         (II)

wherein y is greater than or equal to 1 and less than or equal to 3, andR₁, R₂, R₃, R₄, R₅, n, M⁺ and A⁻ are defined as above, said complex offormula (II) being soluble in said organic solvent.
 2. The process ofclaim 1 comprising a single stage wherein the organic or mineral salt inanhydrous form is contacted with the sequestering agent of formula (I)in solution in said organic solvent.
 3. The process of claim 1comprising a single stage wherein the organic or mineral salt in anaqueous solution is contacted with the sequestering agent of formula (I)in solution in said organic solvent.
 4. The process of claim 1 wherein,in a first stage, the mineral or organic salt in solution in a thirdsolvent is contacted with the sequestering agent of formula (I) insolution in said third solvent; in a second stage, said third solvent iseliminated; and in a third stage, the product resulting from the secondstage is contacted with said organic solvent.
 5. The process of claim 1wherein, in a first stage, the organic or mineral salt in anhydrous formis contacted with the sequestering agent of formula (I) in the absenceof solvent; and, in a second stage, the product resulting from the firststage is contacted with said organic solvent.
 6. The process of claim 1,2, 3, 4 or 5 wherein, in formula (I), R₁, R₂, R₃ and R₄, which can bethe same or different, are each a hydrogen atom or a methyl radical. 7.The process of claim 1, 2, 3, 4 or 5 wherein, in formula (I), n is aninteger from 0 to 6 inclusive.
 8. The process of claim 1, 2, 3, 4 or 5wherein, in formula (I), R₅ is an alkyl radical having 1 to 4 carbonatoms.
 9. The process of claim 1, 2, 3, 4 or 5, wherein, in formula (I),R₁, R₂, R₃ and R₄, which can be the same or different, are each ahydrogen atom or a methyl radical; n is an integer from 0 to 6inclusive; and R₅ is an alkyl radical having 1 to 4 carbon atoms. 10.The process of claim 9 wherein the sequestering agent of formula (I) istris(3,6-dioxaheptyl)amine.
 11. The process of claim 9 wherein thesequestering agent of formula (I) is tris(3,6,9-trioxadecyl)amine. 12.The process of claim 9 wherein the sequestering agent of formula (I) istris(3,6-dioxaoctyl)amine.
 13. The process of claim 9 wherein thesequestering agent of formula (I) is tris(3,6,9-trioxaundecyl)amine. 14.The process of claim 9 wherein the sequestering agent of formula (I) istris(3,6-dioxanonyl)amine.
 15. The process of claim 9 wherein thesequestering agent of formula (I) is tris(3,6,9-trioxadodecyl)amine. 16.The process of claim 9 wherein the sequestering agent of formula (I) istris(3,6-dioxadecyl)amine.
 17. The process of claim 9 wherein thesequestering agent of formula (I) is tris(3,6,9-trioxatridecyl)amine.18. The process of claim 9 wherein the sequestering agent of formula (I)is tris(3-oxabutyl)amine.
 19. The process of claim 9 wherein thesequestering agent of formula (I) istris(4-methyl-3,6-dioxaheptyl)amine.
 20. The process of claim 9 whereinthe sequestering agent of formula (I) istris(2,4-dimethyl-3,6-dioxaheptyl)amine.
 21. The process of claim 1wherein the cation M⁺ is selected from the group consisting of thecation NH₄ ⁺, the cations RNH₃ ⁺ wherein R is an alkyl radical or anaryl radical, and the cations derived from a metal selected from thegroup consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Sc, Y, La, amember of the lanthanide series, Ac, a member of the actinide series,Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Co, Ni, Ru, Rh, Pd,Os, Ir, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, Tl, Ge, Sn, Pb, Sb andBi.
 22. The process of claim 1 wherein the anion A⁻ is selected from thegroup consisting of SCN⁻, O═C═N⁻, Cl⁻, Br⁻, I⁻, F⁻, CN⁻, SH⁻, S.sup.═,OH⁻, HSO₃ ⁻, C10₄ ⁻, BrO₄ ⁻, NH₂ ⁻, NO₃ ⁻, NO₂ ⁻, BF₄ ⁻, BrO⁻, C10⁻, BH₄⁻, SO₃ ⁻⁻, PO₃ ⁻³, CO₃ ⁻⁻, SO₄ ⁻⁻, C10₃ ⁻, BrO₃ ⁻, H⁻ and AlH₄ ⁻. 23.The process of claim 1 wherein the anion A⁻ is selected from the groupconsisting of the anions derived from alcohols, phenols, thiols,thiophenols, acids, amines, amides, organic compounds with mobilehydrogen, and silanols.
 24. The process of claim 1 wherein said organicsolvent is selected from the group consisting of hexane, cyclohexane,benzene, toluene, o-xylene, m-xylene, p-xylene, chlorobenzene,o-dichlorobenzene, 1,2,4-trichlorobenzene, chloroform, methylenechloride, carbon tetrachloride, 1,2-dichloroethane,1,1,1-trichloroethane, 1,1,2-trichloroethane,1,2,2-trichloro-1,1,2-trifluoroethane, perchloroethylene, acetone,acetonitrile, dimethylformamide, N-methylpyrrolidone, dimethylacetamide,hexamethylphosphorotriamide, dimethylsulfoxide, sulfolane, methanol,ethanol and isopropanol.
 25. The process of claim 1 wherein thecontacting is effected at a temperature of between about -50° C. andabout 250° C.
 26. The process of claim 1 wherein the sequestering agentof formula (I) is used in an amount such that the molar ratio of thesequestering agent to the A⁻ M⁺ salt is between about 0.001 and about50.
 27. A complex of the formula:

    [N[CHR.sub.1 --CHR.sub.2 --O--(CHR.sub.3 --CHR.sub.4 --O).sub.n --R.sub.5 ].sub.3 ].sub.y (M.sup.+ A.sup.-)                         (II)

wherein y is a number from 1 to 3 inclusive; n is an integer from 0 to10 inclusive; R₁, R₂, R₃ and R₄, which can be the same or different, areeach a hydrogen atom or an alkyl radical having 1 to 4 carbon atoms; R₅is a radical selected from the group consisting of an alkyl radicalhaving 1 to 12 carbon atoms, a cycloalkyl radical having 3 to 12 carbonatoms, a phenyl radical, a radical of the formula ##STR44## and aradical of the formula ##STR45## m is an integer from 1 to 12 inclusive;A⁻ is an organic or mineral anion; and M⁺ is a cation selected from thegroup consisting of the cation NH₄ ⁺ and its derivatives and the cationsderived from the metals of the groups I_(A), II_(A), III_(A), IV_(A),V_(A), VI_(A), VII_(A), VIII, I_(B), II_(B), III_(B), IV_(B) and V_(B)of the periodic table.
 28. A complex of claim 27 wherein R₁, R₂, R₃ andR₄, which can be the same or different, are each a hydrogen atom or amethyl radical.
 29. A complex of claim 27 wherein n is an integer from 0to 6 inclusive.
 30. A complex of claim 27 wherein R₅ is an alkyl radicalhaving 1 to 4 carbon atoms.
 31. A complex of claim 27 wherein R₁, R₂, R₃and R₄, which can be the same or different, are each a hydrogen atom ora methyl radical; n is an integer from 0 to 6 inclusive; and R₅ is analkyl radical having 1 to 4 carbon atoms.
 32. A complex of claim 31,having the formula:

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.3).sub.3 ].sub.y (A.sup.- M.sup.+).


33. A complex of claim 31, having the formula:

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.3).sub.3 ].sub.y (A.sup.- M.sup.+).


34. A complex of claim 31, having the formula:

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.2 H.sub.5).sub.3 ].sub.y (A.sup.- M.sup.+).


35. A complex of claim 31, having the formula:

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.2 H.sub.5).sub.3 ].sub.y (A.sup.- M.sup.+).


36. A complex of claim 31, having the formula:

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.3 H.sub.7).sub.3 ].sub.y (A.sup.- M.sup.+).


37. A complex of claim 31, having the formula:

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.3 H.sub.7).sub.3 ].sub.y (A.sup.- M.sup.+).


38. A complex of claim 31, having the formula:

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.4 H.sub.9).sub.3 ].sub.y (A.sup.- M.sup.+).


39. A complex of claim 31, having the formula:

    [N--(CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--C.sub.4 H.sub.9).sub.3 ].sub.y (A.sup.- M.sup.+).


40. A complex of claim 31, having the formula:

    [N--(CH.sub.2 --CH.sub.2 --O--C.sub.4 H.sub.9).sub.3 ].sub.y (A.sup.- M.sup.+).


41. A complex of claim 31, having the formula:

    [N--(CH.sub.2 --CH.sub.2 --O--CHCH.sub.3 --CH.sub.2 --O--CH.sub.3).sub.3 ].sub.y (A.sup.- M.sup.+).


42. A complex of claim 31, having the formula:

    [N--(CH.sub.2 --CHCH.sub.3 --O--CHCH.sub.3 --CH.sub.2 --O--CH.sub.3).sub.3 ].sub.y (A.sup.- M.sup.+).


43. A complex of claim 27, 28, 29, 30 or 31 wherein the cation M⁺ isselected from the group consisting of the cation NH₄ ⁺, the cations RNH₃⁺ wherein R is an alkyl radical or an aryl radical, and the cationsderived from a metal selected from the group consisting of Li, Na, K,Rb, Cs, Mg, Ca, Sr, Ba, Sc, Y, La, a member of the lanthanide series,Ac, a member of the actinide series, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W,Mn, Tc, Re, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cu, Ag, Au, Zn, Cd, Hg,Al, Ga, In, Tl, Ge, Sn, Pb, Sb and Bi.
 44. A complex of claim 27, 28,29, 30 or 31 wherein the anion A⁻ is selected from the group consistingof SCN⁻, O═C═N⁻, Cl⁻, Br⁻, I⁻, F⁻, CN⁻, SH⁻, S.sup.═, OH⁻, HSO₃ ⁻, ClO₄⁻, BrO₄ ⁻, NH₂ ⁻, NO₃ ⁻, NO₂ ⁻, BF₄ ⁻, H⁻, BrO⁻, ClO⁻, BH₄ ⁻, SO₃ ⁻⁻,PO₄ ⁻³, CO₃ ⁻⁻, SO₄ ⁻⁻, ClO₃ ⁻, BrO₃ ⁻ and AlH₄ ⁻.
 45. A complex ofclaim 27, 28, 29, 30 or 31 wherein the anion A⁻ is selected from thegroup consisting of the anions derived from alcohols, phenols, thiols,thiophenols, acids, amines, amides, organic compounds with mobilehydrogen, and silanols.
 46. The process of claim 9 wherein thesequestering agent of formula (I) istris(3,6,9,12tetraoxatridecyl)amine.
 47. The process of claim 9 whereinthe sequestering agent of formula (I) istris(3,6,9,12,15,18hexaoxamonadecyl)amine.
 48. A complex of claim 31,having the formula [N[CH₂ --CH₂ --O--(CH₁ --CH₂ --O)₃ --CH₃ ]₃ ].sbsb.y[M⁺ A⁻ ].
 49. A complex of claim 31, having the formula [N[CH₂ --CH₂--O--(CH₂ --CH₂ --O)₅ CH₃ ]₃ ].sbsb.y (M⁺ A⁻ ].